In response to Marc Cousin <[EMAIL PROTECTED]>: > On Monday 11 February 2008 21:13:17 Bill Moran wrote: > > In response to Marc Cousin <[EMAIL PROTECTED]>: > > > On Monday 11 February 2008 20:46:09 Bill Moran wrote: > > > > In response to Marc Cousin <[EMAIL PROTECTED]>: > > > > > > > > [snip] > > > > > > > > > Still, I'd like to know if the md5 field is always a multiple of 32 > > > > > bits in length ? > > > > > > > > md5 is _always_ exactly 128 bits. It's frequently represented as a 32 > > > > character hex string, but that's just a friendly way to display it. > > > > > > > > If you use a bytea field (for example) you can lock it in at 128 bits. > > > > That will help overall by only taking up 20 bytes instead of 36 bytes > > > > for the text string representation, but you have the 4-byte length > > > > header either way. > > > > > > Yes but in the md5 field, we can also have sha1 or sha256. And maybe > > > something else in the future ? > > > Those 3 are 128, 160 and 256 bits, so they are ok for my algorithm... I > > > bet I should just work with this assumption > > > > Just thought of something else. With Postgres, the DB also does > > compression behind the scenes. An md5 (or sha1 or anything else for > > that matter) is probably going to compress down to the same size > > regardless of how it's represented (since it's the same amount of > > entropy) ... so you're probably not going to gain anything by messing > > with the representation. > > > > I don't know how much of this applies to MySQL. > > Postgresql only compresses when the field is bigger than 2kb (via toast) > see : http://www.postgresql.org/docs/8.2/interactive/storage-toast.html
Ahh ... good point. -- Bill Moran Collaborative Fusion Inc. http://people.collaborativefusion.com/~wmoran/ [EMAIL PROTECTED] Phone: 412-422-3463x4023 ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Bacula-devel mailing list Bacula-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-devel
